Diving Line

[SamT]

We were talking in the pub on saturday about dive line (as you do) and to me - the idea of putting reflective tape tabs on the dive line is an awesome one.

I have seen it used to great effect in large caves for marking paths through big chambers.

Someone said on here that you would soon loose the effect in bad vis - fair do's, but think about how good cats eyes are in fog.

This analogy got me thinking that in the same way that you dont use Full Beam in fog due to glare - prehaps lots of bright dive lights are not the answer in bad vis.

just a thought

 

[Pitlamp]

That's a really interesting suggestion Sam (about reflective tape). I must have a rummage in the Screwfix catalogue to see if they do it. Or does anyone else know where it can be sourced?

Your point about bright lamps in bad vis is right - provided the bad vis is due to suspended particles. (If it's due to peat staining then you want as bright a light as you can get, since soluble coloured materials absorb light very easily but can be overcome by blasting them with more light.) If you are diving in a siltout extinguish all helmet mounted lamps and instead go for one hand held. (I have cave dived with folk from Eastern European countries who routinely mount 50 watt lamps on their forearms for this reason.)

 

[SamT]

Not really my idea - but inspired by this thread - reflective line.

Googling "reflective tape" brings back a load of results and theres allsorts on Ebay.

It was used on the berger trip last year to mark key junctions the path back through the woods.

 

[Johnny]

Beer makes you really creative, sometimes

The conversation was with Ink Sump in mind, as we will be using the route through it regularly and you get silted out after the first man has gone through, we were discussing what could be done to help make things safer.
Out arrows made from old plastic signs covered with reflective tape and attached to the line with cable ties was one idea.

I found this;
http://www.indigoshop.co.uk/cat--Reflective-Tape--reflective

Not cheap at £25 for 10m!

 

[Marcus]

For places with crap vis, like Ink or P8 (other than the first man, as stated) QXL3s (glow worms) were the dog's nadgers. Think the Super Pelilights will be similar, but yet to try them out.

Bear in mind, however, that you don't dive in places like these for the scenery. Reflective line / markers are no substitute for good basic skills. If you're in crap vis, you don't expect to see much of the line. If you DO lose the line, and can't find it with a search reel, reflective markers aren't going to make a lot of difference. Having said that, occasional "out" arrows can be reassuring, especially if you think you may have been turned around at some point.

Then again, coming out of Ink with your lights switched off can be good training, and not really make a lot of difference!

Stay safe,

Marcus

 

[Reeve]

Thanks for your advice Gents.

I don't have a problem with using the poly line, it's a bit fiddly but nice and 'feelable' in our nice warm waters...

I have found a good nylon line supplier but it's £30 for 200m :shock:

Thanks again

Dave

The polypropolene from ropesandtwines is fine I think I paid approx £22 plus vat & p&p for 1000m of 4mm. Looking at the site it's now down to £17.50

Just make sure it's well belayed or it'll float & if you make your own reel add some weight to it (put some lead in handle etc) or don't let it go.

Amercan stuff is usually braided nylon or polyester yarn - thicker stuff is gold coloured (Gold Line) as used as permanent line in caves whereas most divers use white braided line for jump/emergency reels.

 

[Duncan Price]

I've used a lot of 4 mm hawser laid polypropylene at £5 for 200 m or so from Woods Group army surplus in Credition Devon. They have a room full of the stuff and also stock 6 mm line - though I think I must have bought most of it. My favourite colour for visibilty in murky sumps is yellow though we've put out 650 m of the orange stuff through the Pwll-y-Cwn - Daren sump when we relined it a couple of years back. I put numbered tags of white PVC insulation tape every 5 m also with green and red cable ties as back up markers - leaving the green (way out) tail longer than the red allows direction finding in zero vis. We put the new line in 20 m sections with big numbered tablets every 50 m. Eventually most lines get covered in silt which needs cleaning off.

I also have reels and reels full of yellow fluorscent braided 2 mm nylon builders twine for use abroad or as search reels in the UK - it take some care handling it as its very soft when wet.

There was some glow in the dark line (well not exactly) called "Glowline" which used to be found in sumps all over the UK - I took a load out of the Silica mines in the '80's as it was a hazard. I also have some glow in the dark line arrows but obvoiusly the effect does not last forever.

 

[Rhys]

Over the last couple of years I've noticed some tents with reflective guy lines. 3mm ish cord with a reflective strand woven in. It might not be cheap, but must be availible somewhere. It's really helped me avoid tripping over a few tents after the pub.

Rhys

 

[Steve_T]

do you cave divers ever use a reflective line?

Back in the late seventies/ early eighties we did try stuff called 'glowline'
Is that stuff still around?
It was plastic coated with a flourescent orange. similar to washing line in feel.
When new it was very visible but once coated in silt it tended to lose its only advantage. The main problem with it was tying knots in it was pretty dodgy so it soon lost its popularity.
I still think the blue polyprop is one of the more visible lines, standing out from the silt much beter than the orange variety.

 

[Armchair]

'Glowline' was indeed nasty stuff, looking deceptively comforting (as clotheslines do), yet having a fiendish tendency to untie itself in both the long- and short-term. If you find any, best pull it out and burn it.

 

[Scoff]

1980's Glowline was bright orange hence easy to see, but the plastic outer was thicker than the coating on washing line, hence Glowline had more plastic memory and a resulting poor reputation, Having said that, it did not undo itself unless your knot-tying was sloppy.

Plastic coated washing line knots easier and stays knotted much better than Glowline - hence I have just replaced the first 200+m of the upstream Hurtle line with nice bright lemon-coloured 4mm washing line. There were no problems with knotability. Better still, the plastic sheath certainly does not catch and hold silt like hawser lay polyprop. Some of the 'bright blue' polyprop I have removed was absolutely black thanks to silt and peat staining. Clothes line also stands up to abrasion better than polyprop - which shreds and forms pretty but hazardous fronds....

The washing line I've used has a polyprop core with pvc outer and seems less floaty and tangly than polyprop hawser lay. Just make sure you do not get hold of wire-cored washing line by mistake, as it is very difficult to cut...

With regards to knotting plastic coated line, just remember to use proper knots such as double fishermens and figure-of-nines. Make certain it won;t come undone by then taping up the tail end with suitable tape. Sticking distance marker tags just requires a few turns of tape before making a 'flag' which is then double back under itself to stick glue to glue.

So, please do not rip out and burn just any old plastic coated line.

Especially if you are in Hurtle.... )


Scoff

(BPC/ CDG Northern Section)

 

[Armchair]

A fair and obviously much more considered point. When glowline was first introduced, knot tying certainly wasn't the skill it is now, where personal line preference can be taken into account without compromising safety. Sincerely hope the Hurtle lines - and any other similar ones - remain intact!

 

[Scoff]

The Hindenburg is always a problem due to debris being washed down and also insufficient stable natural belays on the face.

But the real challenge will be The Void. After our original exploration line got shredded in the first couple of months, me & Biffo resorted to 11mm Bluewater. This lasted a matter of months, as I recall.

Later Ian Lloyd and I bought a suitable length of one inch link galvanised steel chain from Settle Coal and installed that (imagine swimming in with 20m of steel chain on a reel!).

But the chain eventually got trashed in a few years....

I am looking forward to the challenge, and suspect a more scientific approach, akin to SRT rigging will be needed. Should keep me occupied for a little while.

By the way, I've used reflective tags in the past, and they work okay to a point. Trouble is, if the viz is only one metre, tags 5m apart are only seen when you get to them. Much of my gear is covered in reflective tape (much to the chagrin of underwater photographers) as I once put a black depth gauge down on a black mud floor in murky water & never saw it again.

Scoff

BPC/ CDG Northern Section.

 

[Johnny]

By the way, I've used reflective tags in the past, and they work okay to a point. Trouble is, if the viz is only one metre, tags 5m apart are only seen when you get to them. Much of my gear is covered in reflective tape (much to the chagrin of underwater photographers) as I once put a black depth gauge down on a black mud floor in murky water & never saw it again.

Sounds like a good plan to me Scoff, where do you get your reflective tape from?

 

[Scoff]

Dave,

Previously got it in Halfords (yellow, red & white varieties). Don't know if they still stock it. If not Google provides various options (eg. Cyberglow). Or decent haberdashers or outdoor material suppliers (eg. Pennine Outdoor materials at Bentham).

Cheers

Scoff

BPC/ CDG Northern Section

 

[Steve_T]

When glowline was first introduced, knot tying certainly wasn't the skill it is now

Eh?

Was that said tongue in cheek? As Im sure the skill of knot tying predates 1970's cave diving by a year or two. In fact if memory serves me correctly, the double fisheman's was indeed the bend of choice for joining glowline even in those dim and distant days.
More likely our diving skills rather than knot tying abilities (or mine anyway) were not sufficient to hastily join two lines when one or both were glowline, whilst wearing thick gloves and in low visibilty, when all I really wanted to do was get out of there.
Incidentally, not wishing to discredit clothes line, the comparison was merely made to describe an approximation to its appearance to those unfamiliar with the product. :wink: